Roulette's number of randomness depends upon the perfect balance of the wheel. A wheel that is not perfectly maintained may cause certain numbers to show more often than probabilities may dictate. Although these wheels are pretty hard to find, roulette players are always looking for them. During their search, many players simply watch the scoreboards (if the tables have them) or otherwise keep track of the numbers that seem to repeat more often than others. However, a number that shows two or three times within a few roles does not mean that the wheel is necessarily biased. Bias is determined only after monitoring the wheel for thousands of spins-called clocking the wheel- and finding numbers that consistently repeat more than once in 38 spins. And keep in mind that most casino's frequently check their roulette wheels, making certain that they are perfectly balanced.